Weed control of various types has long been practiced by the efficient farmers to maximize production of cultivated lands. Within the last view years, a new method of weed control that is particularly useful with crops such as soybeans and cotton has evolved, namely, the use of a so-called "wick applicator".
While a variety of wick applicators are commercially available, a typical example of a wick applicator is shown in U.S. Pat. No. 4,187,638 issued Feb. 12, 1980 to Hardy et al. In present day wick applicators as well as that illustrated in the above identified patent, a plurality of rope-like wicks have both ends in fluid communication with a reservoir of herbicide. The herbicide, through capillary action, substantially saturates the wicks.
Structure is provided for mounting the wicks in varying ways so that they may be passed over a planted area just above the tops of the plants being cultivated, such as soybeans, and below the tops of the weeds. Consequently, the weeds contact the rope-like wicks and as a result, the herbicide oozes from the wick onto the weeds to kill or otherwise control them.
Such wick applicators have a sizable advantage over other forms of herbicide application in that, at least in theory, the only herbicide used is that which is rubbed off the wick by the weed being contacted with the wick so that no more herbicide than is necessary is used. To a large degree, this is accomplished and relatively small quantities of herbicide may be used for weed control over relatively large areas thereby minimizing the cost of herbicide used for weed control.
However, while the use of wick applicators has resulted in a considerable advantage in the above respect, modern day wick applicators still are not as efficient as they might be. Not infrequently, a wick will be saturated to a greater degree than necessary with the herbicide with the consequence that the herbicide may drop from the wick simply under the influence of gravity or may be splashed from the wick during vibration occurring during operation of a vehicle utilized to move the wick applicator through a cultivated area, or even upon contact with the weed.
This dripping herbicide is of course lost and/or may fall upon desirable plants in the cultivated area inadvertantly killing them or reducing their yield.
Even more frequently, conventional wick applicators provide too little saturation of the wicks in order to avoid herbicide loss, resulting in ineffective weed control.